1. Field of the Invention
The present invention relates to a substrate processing apparatus configured to process a substrate and a method of manufacturing a semiconductor device.
2. Description of the Prior Art
In the related art, for example, as a manufacturing process of a semiconductor device such as a dynamic random access memory (DRAM), a substrate processing process for forming a thin film on a substrate is performed. Such a substrate processing process has been performed by using a substrate processing apparatus, which includes a substrate holder configured to hold a plurality of substrates in a state where the substrates are stacked in a horizontal position, an inner tube configured to accommodate the substrate holder, an outer tube configured to enclose the inner tube, a source gas supply unit configured to supply a source gas such as a film-forming gas or oxidation gas to the inside of the inner tube, and an exhaust unit configured to exhaust gas from a space between the outer and inner tubes so as to create a gas flow inside the inner tube. A film-forming gas or oxidation gas is horizontally supplied between substrates loaded in the inner tube.
However, in the related-art substrate processing apparatus, the velocity of source gas supplied to the center part of a surface of an upper or lower substrate among a plurality of substrates held in the substrate holder is relatively lowered, and thus the uniformity of substrate processing can be deteriorated at the substrate or between substrates.